量角器函数返回undefined？

Question

这更像是一个JavaScript问题，但它正在尝试使用量角器测试来实现。

//fileA.js 
element(by.id('page-element').getText().then(function() { 
    var currentPremium = fileB.getSixMonthPremium(); // calls the function in fileB.js 

    element(by.id('page-element').getText().then(function() { 
     console.log(currentPremium); // prints undefined 
     fileB.compareValue(currentPremium, ..., ...,); 
    }); 
}); 


//fileB.js 
this.getSixMonthPremium() = function() { 
    element(by.id('full-premium').isDisplayed().then(function(displayed) { 
     if (displayed) { 
      element(by.id('full-premium').getText().then(function(currentPremium) { 
       console.log('Current Premium - ' + currentPremium); // prints string of $XXX.xx 
       return currentPremium; //seems to be returning undefined? 
      }); 
     } 
    }); 
}); 

当试图使用变量currentPremium它从函数调用返回后，它总是不确定的。我究竟做错了什么？

Answer 1

欢迎使用带有Javascript的异步调用！

您将要从getSixMonthPremium()呼叫中返回承诺，然后在该呼叫恢复后继续工作。

this.getSixMonthPremium() = function() { 
    return new Promise(function(resolve,reject){ 
     element(by.id('full-premium').isDisplayed().then(function(displayed) { 
      if (displayed) { 
       element(by.id('full-premium').getText().then(function(currentPremium) { 
        console.log('Current Premium - ' + currentPremium); // prints string of $XXX.xx 
        resolve(currentPremium); //seems to be returning undefined? 
       }); 
      } 
     }); 
    }) 
}); 

，那么你将做类似下面搞定承诺：

fileB.getSixMonthPremium().then(function(premium){ 
    ...handle premium 
});